Are collectibles list always changing?

[Zetsumei_Tsunarashi]

The list changes daily. Check you timers window to see when the reset time is in your time zone. There's no way to influence what shows up in the list, it's random. Best thing you can do at this point is hold on to your items and keep an eye out for them to show up again.

[ChameleonMS]

Best thing you can do at this point is hold on to your items and keep an eye out for them to show up again.

Yes, I have done this before. When levelling my Cul from 60-70 I was making Loquat Juice for Leve turnins but I had unfortunately left Collectable Synthesis turned on and made 10 before I even realized what I had done. I stuck them in my retainer and sure enough, about 5 days later, it was a Red Scrip turnin item.